swscale: fix yuv2yuvX_8 assembly on x86

use_mmx_vfilter check/fix by commiter
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libswscale/x86/swscale.c

@@ -430,7 +430,7 @@ switch(c->dstBpc){ \
     case 16:                          do_16_case;                          break; \
     case 10: if (!isBE(c->dstFormat)) vscalefn = ff_yuv2planeX_10_ ## opt; break; \
     case 9:  if (!isBE(c->dstFormat)) vscalefn = ff_yuv2planeX_9_  ## opt; break; \
-    default: if (condition_8bit)    /*vscalefn = ff_yuv2planeX_8_  ## opt;*/ break; \
+    case 8: if ((condition_8bit) && !c->use_mmx_vfilter) vscalefn = ff_yuv2planeX_8_  ## opt; break; \
     }
 #define ASSIGN_VSCALE_FUNC(vscalefn, opt1, opt2, opt2chk) \
     switch(c->dstBpc){ \